From 9752381bd9b0dad81bf56c22ca56e382b54635e6 Mon Sep 17 00:00:00 2001
From: Jinbo Wang <jinbwan@microsoft.com>
Date: Mon, 10 Jul 2023 09:48:27 +0800
Subject: [PATCH] Should not delete the project javanature when removing a
 nested .classpath resource file (#2750)

---
 .../core/internal/managers/IBuildSupport.java   |  3 ++-
 .../projects/eclipse/classpath3/.classpath      |  6 ++++++
 .../projects/eclipse/classpath3/.project        | 17 +++++++++++++++++
 .../eclipse/classpath3/resources/.classpath     |  0
 .../EclipseProjectMetadataFileTest.java         | 17 +++++++++++++++++
 5 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/.classpath
 create mode 100644 org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/.project
 create mode 100644 org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/resources/.classpath

diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/IBuildSupport.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/IBuildSupport.java
index c20a4511d2..a96b926dda 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/IBuildSupport.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/IBuildSupport.java
@@ -96,7 +96,8 @@ default void refresh(IResource resource, CHANGE_TYPE changeType, IProgressMonito
 		if (changeType == CHANGE_TYPE.DELETED) {
 			if (IJavaProject.CLASSPATH_FILE_NAME.equals(resource.getName())) {
 				IProject project = resource.getProject();
-				if (ProjectUtils.isJavaProject(project)) {
+				if (ProjectUtils.isJavaProject(project) && (resource.equals(project.getFile(IJavaProject.CLASSPATH_FILE_NAME))
+						|| resource.getProjectRelativePath().segmentCount() == 1)) {
 					ProjectUtils.removeJavaNatureAndBuilder(project, monitor);
 					update(project, true, monitor);
 				}
diff --git a/org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/.classpath b/org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/.classpath
new file mode 100644
index 0000000000..63566ea3fc
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/.classpath
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
+	<classpathentry kind="output" path="target"/>
+</classpath>
diff --git a/org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/.project b/org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/.project
new file mode 100644
index 0000000000..3a992cf7b1
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/.project
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>classpath3</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>
diff --git a/org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/resources/.classpath b/org.eclipse.jdt.ls.tests/projects/eclipse/classpath3/resources/.classpath
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/filesystem/EclipseProjectMetadataFileTest.java b/org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/filesystem/EclipseProjectMetadataFileTest.java
index 8869434fa3..db3d5f70a9 100644
--- a/org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/filesystem/EclipseProjectMetadataFileTest.java
+++ b/org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/filesystem/EclipseProjectMetadataFileTest.java
@@ -28,6 +28,7 @@
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IProjectDescription;
 import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.Path;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.ls.core.internal.ProjectUtils;
 import org.eclipse.jdt.ls.core.internal.managers.AbstractProjectsManagerBasedTest;
@@ -98,4 +99,20 @@ public void testDeleteClasspath() throws Exception {
 		IFile bin = project.getFile("bin");
 		assertFalse(bin.getRawLocation().toFile().exists());
 	}
+
+	@Test
+	public void testDeleteNonMetadataClasspath() throws Exception {
+		String name = "classpath3";
+		importProjects("eclipse/" + name);
+		IProject project = getProject(name);
+		assertNotNull(project);
+		IFile dotClasspath = project.getFile(new Path("resources/.classpath"));
+		File file = FileUtil.toPath(dotClasspath.getLocationURI()).toFile();
+		assertTrue(file.exists());
+		file.delete();
+		projectsManager.fileChanged(file.toPath().toUri().toString(), CHANGE_TYPE.DELETED);
+		waitForBackgroundJobs();
+		project = getProject(name);
+		assertTrue(ProjectUtils.isJavaProject(project));
+	}
 }